1. Field of the Invention
The present invention relates to an antenna, and more particularly to an complex antenna having wider range of frequency band and excellent performance.
2. Description of Prior Art
Wireless communication devices, such as cellular phones, notebook computers, electronic appliances, and the like, are normally equipped with an antenna that serves as a medium for transmission and reception of electromagnetic signals, such as date, audio, image, and so on. However, more and more people dissatisfy their electronic devices only work in WLAN (Wireless Wide Area Network). Making the portable electronic devices working in WWAN (Wireless Wide Area Network) or GPS (Global Positioning System) is a purpose of the many people.
In recent years, WLAN adopts two key technical standards of Bluetooth and Wi-Fi. Bluetooth works in 2.4 GHz, and Wi-Fi works in 2.4 GHz and 5 GHz. However, WWAN adopts three technical standards of GSM (Global System for Mobile Communication), GPS (Global Positioning System) and CDMA (Code Division Multiple Access). Operating frequency bands of the GSM are 900/1800 MHz, and operating frequency band of the GPS is 1.575 GHz. CDMA includes three kinds of technical standards: CDMA2000, WCDMA and TD-SCDMA. Operating frequency bands of the CDMA2000 are 800, 900, 1700, 1800, 1900, and 2100 MHz. Operating frequency bands of the WCDMA are 1800, 1900, and 2100 MHz. Operating frequency bands of the TD-SCDMA are 900, 1800, and 2100 MHz.
Accordingly, an antenna of a notebook must operate in above frequency bands, the portable electronic device is capable of working in WLAN and WWAN. Now, the portable electronic device is usually installed with two antennas for working in the WLAN and WWAN, one antenna working in the WLAN and another antenna working in the WWAN. However, with the development of the miniaturization of the portable electronic device, more and more portable electronic devices are difficult to install two sets antennas in the limited inner space.
Taiwanese patent publication No. 200642171 discloses a multi-band antenna including a WWAN antenna and a WLAN antenna. The multi-band antenna is capable to work in WWAN and WLAN at the same time.
However, the multi-band antenna has narrower range of frequency band, and is not capable to cover all frequency bands of WWAN. In addition, the WLAN antenna and the WWAN antenna extending from common edge of a grounding element influence radiating performance of the antenna.
Hence, in this art, a complex antenna to overcome the above-mentioned disadvantages of the prior art will be described in detail in the following embodiment.